you need to make sure the http service can write the .css
i.e. make sure .../themes/default is writable by the http user on your system

Ok, so I've gotten some success by doing that, but still not 100% yet. Now the page is formatted correctly, but I'm still receiving the invalid status error as soon as the page loads. I'm not sure what I'm doing different this time from the last time I was running the UI.

I ended up moving HDHR-DVRUI to a new computer. I was using a version of XAMPP with 514 and it worked. With the new computer, I couldn't get it work so I tried different versions of XAMPP with different version of HDHR-DVRUI and finally got XAMPP ver 7.1.26-0-VC14 working with HDHR-DVRUI Ver 063. I still have one issue. When I schedule a show to record, I get a pop up error:

If I try to use the latest version, I get this error when starting:
Fatal error: Uncaught Error: Undefined class constant 'DVRUI_DEBUG' in C:\xampp\htdocs\HDHR65\includes\dvrui_debug.php:8 Stack trace: #0 C:\xampp\htdocs\HDHR65\index.php(4): require_once() #1 {main} thrown in C:\xampp\htdocs\HDHR65\includes\dvrui_debug.php on line 8